survcomp (version 1.22.0)

dindex.comp: Function to compare two D indices

Description

This function compares two D indices from their betas and standard errors as computed by a Cox model for instance. The statistical test is a Student t test for dependent samples. The two D indices must be computed using the D.index function from the same survival data.

Usage

dindex.comp(dindex1, dindex2)

Arguments

dindex1

first D index

dindex2

second D index

Value

p.value

p-value from the Wilcoxon rank sum test for the comparison dindex1 > dindex2

dindex1

value of the first D index

dindex2

value of the second D index

Details

The two D indices must be computed using the D.index function from the same samples (and corresponding survival data). The function uses a Student t test for dependent samples.

References

Haibe-Kains, B. and Desmedt, C. and Sotiriou, C. and Bontempi, G. (2008) "A comparative study of survival models for breast cancer prognostication based on microarray data: does a single gene beat them all?", Bioinformatics, 24, 19, pages 2200--2208.

See Also

D.index, t.test

Examples

set.seed(12345)
age <- rnorm(100, 50, 10)
size <- rexp(100,1)
stime <- rexp(100)
cens <- runif(100,.5,2)
sevent <- as.numeric(stime <= cens)
stime <- pmin(stime, cens)
d1 <- D.index(x=age, surv.time=stime, surv.event=sevent)
d2 <- D.index(x=size, surv.time=stime, surv.event=sevent)
dindex.comp(d1, d2)